2GR-FE ENGINE CONTROL SYSTEM
– SFI SYSTEM
ES–141
ES
DESCRIPTION
The Mass Air Flow (MAF) meter is a sensor that measures the amount of air flowing through the valve.
The ECM uses this information to determine the fuel injection time and to prove appropriate air-fuel ratio.
Inside the MAF meter, there is a heated platinum wire which is exposed to the flow of intake air.
By applying a specific electrical current to the wire, the ECM heats it to a given temperature. The flow of
incoming air cools both the wire and an internal thermistor, affecting their resistance. To maintain a
constant current value, the ECM varies the voltage applied to these components in the MAF meter. The
voltage level is proportional to the airflow through the sensor, and the ECM uses it to calculate the intake
air volume.
The circuit is constructed so that the platinum hot wire and the temperature sensor provide a bridge
circuit, and the power transistor is controlled so that the potentials of A and B remain equal to maintain the
predetermined temperature.
HINT:
When any of these DTCs are set, the ECM enters fail-safe mode. During fail-safe mode, the ignition
timing is calculated by the ECM, according to the engine RPM and throttle valve position. Fail-safe mode
continues until a pass condition is detected.
DTC
P0101
Mass Air Flow Circuit Range / Performance
Problem
DTC No.
DTC Detection Condition
Trouble Area
P0101
Test value calculated with engine load and fuel trim are
out of specified threshold under the following conditions
(2 trip detection logic):
–
Engine load is 30 % or more and constant
–
Engine coolant temperature is 70
°
C (158
°
F) or
higher
MAF meter
Temperature Sensor
(Thermistor)
Temperature Sensor (Thermistor)
+B
Power Transistor
Platinum Hot Wire (Heater)
Platinum Hot Wire (Heater)
Output Voltage
A
B
A140749E05
Summary of Contents for 2GR-FE
Page 176: ...ES 20 2GR FE ENGINE CONTROL SYSTEM SFI SYSTEM ES NEXT 20 CONDUCT CONFIRMATION TEST END ...
Page 247: ...2GR FE ENGINE CONTROL SYSTEM SFI SYSTEM ES 91 ES OK REPLACE ECM See page ES 518 ...
Page 412: ...ES 256 2GR FE ENGINE CONTROL SYSTEM SFI SYSTEM ES A END ...
Page 447: ...2GR FE ENGINE CONTROL SYSTEM SFI SYSTEM ES 291 ES OK REPLACE ECM See page ES 518 ...
Page 556: ...ES 400 2GR FE ENGINE CONTROL SYSTEM SFI SYSTEM ES A REPLACE TCM ...
Page 630: ...ES 474 2GR FE ENGINE CONTROL SYSTEM SFI SYSTEM ES OK REPLACE ECM See page ES 518 ...
Page 658: ...2GR FE ENGINE CONTROL SYSTEM VVT SENSOR ES 493 ES 22 INSTALL ENGINE UNDER COVER LH ...
Page 897: ...2GR FE STARTING SMART KEY SYSTEM ST 35 ST OK REPLACE MAIN BODY ECU ...
Page 923: ...2GR FE STARTING SMART KEY SYSTEM ST 61 ST OK REPLACE MAIN BODY ECU ...
Page 935: ...2GR FE STARTING SMART KEY SYSTEM ST 73 ST OK REPLACE MAIN BODY ECU ...
Page 940: ...ST 78 2GR FE STARTING SMART KEY SYSTEM ST OK REPLACE MAIN BODY ECU ...
Page 958: ...ST 96 2GR FE STARTING SMART KEY SYSTEM ST OK END MAIN BODY ECU DEFECTIVE ...